github.com/jackc/pgx/v5 v5.10.0: pgconn.ParseConfig

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/jackc/pgx/v5/pgconn.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.10.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/jackc/pgx/v5@v5.10.0
Demonstrate these symbols/APIs:
  - github.com/jackc/pgx/v5/pgconn.ParseConfig
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@11.8.0
  - runtime: node@24.13.1

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:c235ed8433fbb33528f91efecfb2f2a4c4fb296ab9322e19123855277cd7803a","contract":["pgconn.ParseConfig parses standard PostgreSQL connection URI into Config with host, port, database, user, password, and runtime parameters","pgconn.ParseConfig parses libpq key-value format DSN connection string with connect timeout","pgconn.ParseConfig returns an error when given an invalid connection string","sample helper ParsePgConnConfig extracts connection summary parameters correctly","sample helper BuildCustomPgConnConfig applies default connect timeout when not specified","sample helper BuildCustomPgConnConfig preserves explicit connect timeout from connection string"],"goal":"verify github.com/jackc/pgx/v5/pgconn.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.10.0","kind":"HOW","packages":["pkg:golang/github.com/jackc/pgx/v5@v5.10.0"],"schemaVersion":1,"symbols":["github.com/jackc/pgx/v5/pgconn.ParseConfig"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","ecosystem":"golang","os":"windows","osVersionBucket":"11","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/jackc/pgx/v5@v5.10.0"],"schemaVersion":1,"symbols":["github.com/jackc/pgx/v5/pgconn.ParseConfig"],"verifierAdapter":"golang@1"}

module sample

go 1.26.5

require github.com/jackc/pgx/v5 v5.10.0

require (
	github.com/jackc/pgpassfile v1.0.0 // indirect
	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
	golang.org/x/text v0.29.0 // indirect
)

github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
github.com/jackc/pgx/v5 v5.10.0 h1:VhSvgU2jSli8o3AqIEOTJr7rZwAEUVo4E4XhR94Zfr0=
github.com/jackc/pgx/v5 v5.10.0/go.mod h1:mal1tBGAFfLHvZzaYh77YS/eC6IX9OWbRV1QIIM0Jn4=
github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

import (
	"fmt"
	"time"

	"github.com/jackc/pgx/v5/pgconn"
)

// PgConnSummary represents parsed connection parameters extracted from pgconn.Config.
type PgConnSummary struct {
	Host           string
	Port           uint16
	Database       string
	User           string
	Password       string
	ConnectTimeout time.Duration
	RuntimeParams  map[string]string
}

// ParsePgConnConfig parses a PostgreSQL connection string (URI or DSN) using pgconn.ParseConfig
// and returns a summary struct with extracted connection parameters.
func ParsePgConnConfig(connString string) (*PgConnSummary, error) {
	cfg, err := pgconn.ParseConfig(connString)
	if err != nil {
		return nil, fmt.Errorf("failed to parse connection config: %w", err)
	}

	summary := &PgConnSummary{
		Host:           cfg.Host,
		Port:           cfg.Port,
		Database:       cfg.Database,
		User:           cfg.User,
		Password:       cfg.Password,
		ConnectTimeout: cfg.ConnectTimeout,
		RuntimeParams:  make(map[string]string, len(cfg.RuntimeParams)),
	}

	for k, v := range cfg.RuntimeParams {
		summary.RuntimeParams[k] = v
	}

	return summary, nil
}

// BuildCustomPgConnConfig parses a connection string and applies custom options such as fallback timeout.
func BuildCustomPgConnConfig(connString string, defaultTimeout time.Duration) (*pgconn.Config, error) {
	cfg, err := pgconn.ParseConfig(connString)
	if err != nil {
		return nil, fmt.Errorf("invalid connection string: %w", err)
	}

	if cfg.ConnectTimeout == 0 && defaultTimeout > 0 {
		cfg.ConnectTimeout = defaultTimeout
	}

	return cfg, nil
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/jackc/pgx/v5/pgconn.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.10.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/jackc/pgx/v5@v5.10.0"
  ],
  "symbols": [
    "github.com/jackc/pgx/v5/pgconn.ParseConfig"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@11.8.0",
    "runtime": "node@24.13.1"
  }
}

package main

import (
	"fmt"
	"os"
	"time"

	"github.com/jackc/pgx/v5/pgconn"
	"sample"
)

func main() {
	// 1. Verify pgconn.ParseConfig parses standard PostgreSQL URL
	urlDSN := "postgres://alice:secret123@localhost:5432/my_app_db?application_name=demo_app&search_path=public"
	cfg, err := pgconn.ParseConfig(urlDSN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "ParseConfig(URL) failed: %v\n", err)
		os.Exit(1)
	}

	if cfg.Host != "localhost" {
		fmt.Fprintf(os.Stderr, "expected Host 'localhost', got %q\n", cfg.Host)
		os.Exit(1)
	}
	if cfg.Port != 5432 {
		fmt.Fprintf(os.Stderr, "expected Port 5432, got %d\n", cfg.Port)
		os.Exit(1)
	}
	if cfg.Database != "my_app_db" {
		fmt.Fprintf(os.Stderr, "expected Database 'my_app_db', got %q\n", cfg.Database)
		os.Exit(1)
	}
	if cfg.User != "alice" {
		fmt.Fprintf(os.Stderr, "expected User 'alice', got %q\n", cfg.User)
		os.Exit(1)
	}
	if cfg.Password != "secret123" {
		fmt.Fprintf(os.Stderr, "expected Password 'secret123', got %q\n", cfg.Password)
		os.Exit(1)
	}
	if cfg.RuntimeParams["application_name"] != "demo_app" {
		fmt.Fprintf(os.Stderr, "expected application_name 'demo_app', got %q\n", cfg.RuntimeParams["application_name"])
		os.Exit(1)
	}
	if cfg.RuntimeParams["search_path"] != "public" {
		fmt.Fprintf(os.Stderr, "expected search_path 'public', got %q\n", cfg.RuntimeParams["search_path"])
		os.Exit(1)
	}

	// 2. Verify pgconn.ParseConfig parses libpq key-value connection string
	kvDSN := "host=127.0.0.1 port=5433 dbname=test_service user=bob password=pass connect_timeout=5"
	kvCfg, err := pgconn.ParseConfig(kvDSN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "ParseConfig(KV) failed: %v\n", err)
		os.Exit(1)
	}
	if kvCfg.Host != "127.0.0.1" || kvCfg.Port != 5433 || kvCfg.Database != "test_service" || kvCfg.User != "bob" || kvCfg.Password != "pass" {
		fmt.Fprintf(os.Stderr, "KV config fields mismatch: %+v\n", kvCfg)
		os.Exit(1)
	}
	if kvCfg.ConnectTimeout != 5*time.Second {
		fmt.Fprintf(os.Stderr, "expected ConnectTimeout 5s, got %v\n", kvCfg.ConnectTimeout)
		os.Exit(1)
	}

	// 3. Verify pgconn.ParseConfig returns error on invalid connection strings
	_, invalidErr := pgconn.ParseConfig("://invalid-url-%%")
	if invalidErr == nil {
		fmt.Fprintf(os.Stderr, "expected error for invalid URL, got nil\n")
		os.Exit(1)
	}

	// 4. Verify sample helper ParsePgConnConfig
	summary, err := sample.ParsePgConnConfig(urlDSN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "sample.ParsePgConnConfig failed: %v\n", err)
		os.Exit(1)
	}
	if summary.Host != "localhost" || summary.Database != "my_app_db" || summary.User != "alice" || summary.Port != 5432 {
		fmt.Fprintf(os.Stderr, "summary mismatch: %+v\n", summary)
		os.Exit(1)
	}
	if summary.RuntimeParams["application_name"] != "demo_app" {
		fmt.Fprintf(os.Stderr, "summary application_name mismatch: %+v\n", summary.RuntimeParams)
		os.Exit(1)
	}

	_, sampleInvalidErr := sample.ParsePgConnConfig("://invalid-url-%%")
	if sampleInvalidErr == nil {
		fmt.Fprintf(os.Stderr, "expected sample error for invalid URL, got nil\n")
		os.Exit(1)
	}

	// 5. Verify sample helper BuildCustomPgConnConfig applies default timeout when not specified
	customCfg, err := sample.BuildCustomPgConnConfig("postgres://user:pass@localhost:5432/db", 10*time.Second)
	if err != nil {
		fmt.Fprintf(os.Stderr, "sample.BuildCustomPgConnConfig failed: %v\n", err)
		os.Exit(1)
	}
	if customCfg.ConnectTimeout != 10*time.Second {
		fmt.Fprintf(os.Stderr, "expected default timeout 10s applied, got %v\n", customCfg.ConnectTimeout)
		os.Exit(1)
	}

	// 6. Verify BuildCustomPgConnConfig does not overwrite explicit timeout
	explicitTimeoutCfg, err := sample.BuildCustomPgConnConfig(kvDSN, 10*time.Second)
	if err != nil {
		fmt.Fprintf(os.Stderr, "sample.BuildCustomPgConnConfig with explicit timeout failed: %v\n", err)
		os.Exit(1)
	}
	if explicitTimeoutCfg.ConnectTimeout != 5*time.Second {
		fmt.Fprintf(os.Stderr, "expected explicit timeout 5s preserved, got %v\n", explicitTimeoutCfg.ConnectTimeout)
		os.Exit(1)
	}

	fmt.Println("All pgconn.ParseConfig contract assertions passed.")
}